The subject invention generally relates to ink-jet printer technology, and is directed more particularly to apparatus for priming a thermal ink jet printhead cartridge without removal of the printhead cartridge from the printer carriage.
Thermal ink jet printers commonly utilize printhead cartridges, often called pens, which typically include one or more ink reservoirs and an integrated circuit printhead that includes a nozzle plate having an array of ink ejecting nozzles which emit ink droplets in response to electrical pulses provided to the printhead.
An important consideration with thermal ink jet printhead cartridges is the need to ready a printhead for printing. For example, when a new printhead cartridge is installed in a printer or after a period of non-usage, the cartridge might be unable to produce ink drops at one or more nozzles, for example as a result of foreign contamination of the nozzles, dried ink in the nozzles, or air ingested into the nozzles.
Known systems for priming include those which involve the application of pressure to the ink supply in order to cause ink flow into the ink containing chambers that are adjacent the ink ejecting nozzles. Considerations with such known systems is need for access to the ink reservoir, and the various mechanical impedances between the ink reservoir and the nozzles which reduce the pressure that eventually reaches the nozzles.
Another known system requires that a printhead cartridge be removed from the printer carriage and inserted into a separate priming station for priming, which further requires that the printhead cartridge be removed from the priming station after priming and inserted back into the carriage. Considerations with these systems include the additional wear and tear on the electrical contacts of the printhead cartridge and the printer carriage, as well as the inconvenience of having to perform the remove and insert procedure two times for one priming.
A further known system includes a movable cap that is engageable with a printhead nozzle array and is directly connected to a tube of a peristaltic pump. Considerations with this system, however, include the need for separate pump for each printhead of a multiple printhead carriage, and clogging of the pump tube with ink.